To ensure the safety of the passengers and crewmembers in case of a depressurization accident or the occurrence of smoke in the aircraft, aviation regulations require on board all airliners a safety oxygen supply circuit able to supply each passenger and crewmember with an oxygen flow rate function of the cabin altitude. Such oxygen is delivered to the crewmember or passenger, also known as end user, through a breathing mask.
After a depressurization accident or upon the occurrence of smoke in the aircraft, the crewmembers must don their protective mask upon their face as quickly as possible. Indeed, the lack of oxygen at high altitude (hypoxia) or the toxic fumes can alter the crewmembers' abilities to proceed with any emergency measures that will ensure the safety of the passengers and the aircraft.
A protective mask is generally stored in a box called a stowage box located next to the crewmember's position. Generally, the stowage box comprises a frame forming a receptacle for the mask, itself having an open face of rectangular shape for inserting and extracting the mask, and at least two doors closing the open face of the frame, at least in part. The mask is extracted through the face that is closed by two doors that retain and/or protect the mask, each opening and closing about a respective hinge, the two hinges of the doors operating about two parallel hinge axes. The box is installed on the right or left of the seat of the pilot, the open face being generally the top side of the box. The stowage box comprises a pneumatic assembly able to close the feed of breathing gas of the breathing mask when the breathing mask is installed in the stowage box. The objective of the pneumatic assembly is to reduce or suppress the consumption of breathing gas when the mask is not in use. Therefore, the pneumatic assembly is connected to one of the doors of the box such that the feed of breathing gas is closed when the doors are closed and is open when the doors are open.
For instance, patent application US 2004/0144384 discloses such a box.
Problem with such a box is the occupied space in small aircraft. The known boxes are well suited for large aircraft, typically able to transport 100 passengers and more, in which the pilot cabin is large enough.
However, in small passenger aircrafts, typically able to transport between 10 and 80 passengers, the pilot cabin is crowded by all the equipments used to control the aircraft. And there is no space available around the seats of the pilots to install a stowage box as known in the prior art.